It is to be stressed that when a Muslim prays he asks none but Allah and when he seeks help, he seeks the help of Allah alone. We pray to Allah, not to any creature, including the Prophets and Messengers of Allah.

Elaborating more on this issue, we’d like to furnish you with the following fatwa issued by Dr. Muzammil H. Siddiqi, President of the Fiqh Council of North America, states: “The Prophet (peace and blessings be upon him) himself told us in a very authentic hadith that is reported by `Abdullah ibn `Abbas (may Allah be pleased with him), “When you ask something, you ask in the name of Allah and when you seek help, you seek help of Allah. Know that if the people were to gather together to benefit you with anything it would benefit you only with something that Allah had already prescribed for you and that if they gathered together to harm you with something, they would harm you only with something Allah had already prescribed for you.” So the Sunnah is that we pray to Allah (Mighty and Exalted be He).
Tawassul means that in our du`a’, we mention also the salat and salam (seek peace and blessings) for the Prophet Muhammad, or we show our love and our faith in Prophet Muhammad (peace and blessings be upon him), so in this way our prayer becomes more acceptable to Allah, but we must always pray to Allah, not to any creature, including the Prophets and Messengers of Allah. There is no authentic hadith which teaches that Muslims should pray with the words, “Ya Muhammad” “Yas Rasul Allah”, and the Companions of the Prophet also did not do that and we should follow the way of our Prophet (peace and blessings be upon him) and his Companions in our prayers. Prophet Muhammad (peace and blessings be upon him) was the last and the final Messenger of Allah. He is the beloved of Allah (Habibullah). We believe in him, honor him, respect him and love him, but we do not worship him or come to Allah through him.”

Clarifying the Islamic ruling regarding Tawassul, we would like to cite for you the following fatwa issued by Sheikh Ahmad Kutty, a senior lecturer and Islamic scholar at the Islamic Institute of Toronto, Ontario, Canada , in which he states the following:

“A number of things should be clear in the mind of every Muslim:

1.In Islam, we must not ask, pray, or supplicate to any one other than Allah. This is why we repeat several times a day in our prayer, “You alone do we worship, and from You alone we seek assistance.” (Al-Fatihah: 5)

2. The Prophet (peace and blessings be upon him) told his cousin, Ibn `Abbas, “…if you ask, ask of Allah, if you seek assistance, seek assistance from Allah.”

3. In the Qur’an, Allah tells us that He is “closer to us than our own jugular vein” (Qaf: 16), and that He knows our innermost thoughts, before we even express them.

4. He (Allah) also guarantees that no matter how ugly our sins are, we can always call upon Him directly, without any intermediary. He has also promised to answer us, so long as
we turn to Him sincerely.

In the light of what we said above, no Muslim must think that there is any justification in Islam for calling upon anyone other than Allah. To do so would be nothing short of shirk or associating partners with Allah. Such a practice never existed in the best generations of Islam. We are told to follow their example in religion.

Moreover, according to the Qur’an, the pagans of Makkah who called upon deities other than Allah are cited as saying, “we only worship them in order to bring us closer to Allah.” (Az-Zumar: 3) And “They are our intercessors before Allah.” (Yunus: 18) It is, therefore, safe to conclude that the practice of calling upon saints, dead or alive, is nothing but a form of shirk. No Muslim should ever contemplate such a practice, if he/she is keen on keeping his/her religion intact.”

Moreover, it seems useful to sum up the following points from the book Dustur al-Wahdah ath-Thaqafiyyah (The Constitution of Cultural Unity) with regard to the different kinds of Tawassul:
First,tawassul or invoking Allah the Most High, through His Being (Dhat) and Most Beautiful Names made in such way is mentioned in the following hadiths:
1. The hadith which reads: “O Allah! I implore You by virtue of Your being Allah, the One, Who has no partner, the Eternal, Absolute, Who begetteth not, nor is He begotten, and like unto Whom there is none.”
2. The Prophetic supplication for memorizing the Qur’an, “O Allah! I beseech You by virtue of Your Glory and by the Light of Your Face to let me keep Your Book by heart as You have taught me.”
3. The supplication, “O Allah! I seek refuge with Your pleasure from Your wrath and with Your pardon from Your punishment.” Undoubtedly, there is no harm in such forms of tawassul.
Second, tawassul of a person to Allah, the Most High through showing obedience to Him as well as through his own good deeds which are done only for His sake. This meaning is involved in the verse that reads, “O ye who believe! Do your duty to Allah, seek the means of approach unto Him, and strive (with might and main) in His cause: that ye may prosper.” (Al-Ma’idah: 35)
there is also a long Hadith speaking about three men who were trapped in a cave by a great stone, and nothing saved them but their supplications to Allah, each using a means through his best deed. This comes in accordance with the Hadith, “Get to know Allah in prosperity and He will know you in adversity.”
Third, tawassul through the righteous people’s supplications and the supplications of Muslims, one for the other, has been established since the time of Prophet Nuh (peace and blessings be upon him) who supplicated to Allah saying, “O Lord! Forgive me, my parents, all who enter my house in Faith, and (all) believing men and believing women: and to the wrong–doers grant Thou no increase but in Perdition!” (Nuh: 28)
Such supplication is recommended and rewarded by Allah, whether it is said in the presence of the one on whose behalf it is made or in his absence. The angels and the bearers of the Throne continuously supplicate: “Our Lord! Thou embraced all things in Mercy and Knowledge, forgive, then, those who turn in repentance, and follow Thy Path; and preserve them from the Chastisement of the Blazing Fire!” (Ghafir: 7)
Late Muslims supplicate for the sake of the early Muslims as a token of the unity of believers in their being all servants of Allah regardless of difference in time and place: “And those who came after them say, ‘Our Lord! Forgive us, and our brethren who came before us into the Faith, and leave not, in our hearts, rancour (or sense of injury) against those who have believed.” (Al-Hashr: 10)
the Muslim Ummah supplicates for the sake of the Messenger of Allah (peace and blessings be upon him) after prayer and adhan out of their love and reverence to him.
the Companions (may Allah be pleased with them) used to ask the Messenger of Allah to supplicate to Allah to bring them rain. After the death of the Prophet (peace and blessings be upon him) they asked Al-`Abbas, the Prophet’s uncle, to supplicate to Allah to give them rain due to his relation to the Prophet (peace and blessings be upon him).
In Islam, there is nothing wrong in asking your righteous Muslim brother to supplicate to Allah on your behalf.
Fourth, tawassul through the person of the Prophet (peace and blessings be upon him) and Allah’s love to him; concerning the ruling of this form of tawassul, I have found two opinions:
i) There is nothing related in this concern and the supplications mentioned in the Glorious Qur’an and the Sunnah involve direct invocation to Allah. Therefore, it is more proper that we follow this direct style.
ii) Supplication to Allah through the person of Prophet (peace and blessings be upon him) was related in the narration which states that a blind man sought intercession of the Prophet with his Lord on his behalf in a supplication that he had learned from the Prophet, or from others, and when he said that supplication his sight was restored. Those who state that opinion add that this form of tawassul was reported in more than ten ways (of transmission), and this is a testimony on its behalf, although it was not narrated in the two Sahihs of al-Bukhari and Muslim.
however, the two parties disputed to the extent that they were about to fall into a prolonged rupture of relations. Both parties committed faults. For example, one of them accused the other of polytheism, and the latter described the former as hating the Prophet (peace and blessings be upon him). This resulted in more division among them. The issue became worse when the second sect drew analogy between the person of the Prophet (peace and blessings be upon him) and others whom they thought to be righteous and awliya’ (saints). They, moreover, neglected the authenticated supplications and indulged in formulas of supplications about which there is more than one opinion.
these people committed a mistake when they drew analogy
between the person of the Prophet (peace and blessings be upon him) and others. Analogy should not be applied to acts of worship. They should have mainly used what is proven as authentic in the Qur’an and the Sunnah.
as for those who depict Muslims with polytheism, they should refrain from this and stop judging people depending only on mere ill thinking.
Fifth, tawassul through asking those who are close to Allah, as to ask a dead Prophet or a wali at his grave to fulfill one’s request. This form of tawassul is unanimously rejected in Islam, for it is a form of polytheism. What prevents those who commit this heinous act from asking Allah, Who is nearer to them than their jugular veins, and Who is the only One Who can fulfill all their requests?
however, it seems that the difference between those who regard tawassul through the person of the Prophet (peace and blessings be upon him) as permissible and those who do not, is like the difference between two religions. In their reactions to this issue, some scholars delivered incorrect judgments.”