It should be clear that it is Sunnah to diligently perform the Non obligatory Prayers that are offered before and after the obligatory ones. A Muslim should go to the mosque so early to perform the sunnah Prayer before raising the Iqamah. If the Iqamah is raised while a worshiper is still offering the sunnah Prayer, he can complete the sunnah Prayer if he will be able to join the first rak`ah with the congregation.
Sheikh Ahmad Kutty, a senior lecturer and Islamic scholar at the Islamic Institute of Toronto, Ontario, Canada states: “The Prophet (peace and blessing be upon him) said: “When the final call to salah (ritual Prayer) has been given, there is no other salah except the obligatory one” (Muslim). Based on this hadith, one is not supposed to initiate a sunnah Prayer (regardless of how strongly recommended it is) after the Iqamah has been called. However, if a person had already started the sunnah Prayer before the Iqamah was called, then he should consider this: If he can easily finish his sunnah and still join the imam in the first rak`ah (unit of Prayer), then he is allowed to continue his Prayer; otherwise, he must release himself from his salah by Tasleem and then join the imam as soon as possible.
There are various other shades of opinions on this issue, but the dispute concerning it can be readily settled by quoting the final word of Imam Ibn `Abd Al-Barr: “In case of a dispute the only proof that can be relied upon is the Sunnah, and whoever sticks to it he is
indeed successful. Therefore to refrain from praying non-obligatory salah after the Iqamah and making up for it later is closest to compliance with the Sunnah. This idea can be further confirmed if one were to reflect upon the call ‘Come to salah,’ which means come to the salah for which the final call has been made, and hence, the most fortunate ones are those who readily respond to the summons by leaving everything else.”
As implied in the above statement of Imam Ibn `Abd Al-Barr, one who is worried about missing an important sunnah because of his refraining from performing the sunnah Prayer after the Iqamah can find consolation in the fact that it can be done after the obligatory Prayer. That it is permissible to make up for sunnah even after the Fajr Prayer can be inferred from the hadith reported by Abu Dawud: The Prophet (peace and blessings be upon him) saw a man praying two rak`ahs after Fajr Prayer; when he asked him what he was doing, he told the Prophet that he was making up for the two rak`ahs of sunnah he had missed. The Prophet (peace and blessings be upon him) approved of his act, as he did not say anything to him. It is inconceivable that he would have done so if it had been forbidden to pray the sunnah Prayer after Fajr Prayer.”