Having children is a blessing from Almighty Allah Who bestows them upon whom He wills from among His servants. Almighty Allah says, [Unto Allah belongs the sovereignty of the heavens and the earth. He creates what He will. He bestows female (offspring) upon whom He will, and bestows male (offspring) upon whom He will; Or He mingles them, males and females, and He makes barren whom He will. Lo! He is Knower, Powerful.] (Ash-Shura 42: 49-50) Therefore, having a son is only in the hands of Almighty Allah and taking a second wife may not be the proper solution in this case.
Sheikh Ahmad Kutty, a senior lecturer and Islamic scholar at the Islamic Institute of Toronto, Ontario, Canada, states: Although the wish to have a son is natural, it is my earnest opinion that one is not justified in taking another wife solely for that reason.
First of all, how can we be sure that they will be granted a son, even if they were to remarry?
In other words, if one comes from a culture where taking more than one wife is not the societal norm and that the wife would not have married if she ever suspected that one would do so, then the husband definitely needs to obtain her permission before taking a second wife. The Prophet (peace and blessings be upon him) said, “Of all the terms we enter into, there is none more worthy of compliance than the conditions we enter into while contracting marriages.” There is no reason to limit these conditions to those that have been written. It is, therefore, reasonable for us to suppose that they must also include all the verbal as well the tacit agreements that are simply assumed or taken for granted in a particular culture or society unless they are in clear violation of Shari`ah. Jurists also tell us that the customs and norms of a society, unless otherwise contradicted by Shari`ah, have the force of law. Therefore, it would be unjust and unfair on your part to simply go ahead and get married without your wife’s consent. A husband in this situation is therefore best advised to be content with Allah’s will and choice for the. They may do so by consistently meditating on the following supplication:
allahumma ij`al lee nafsan mutma’innatan tu’minu bi liqa’ika, wa taqna`u bi `ata’ika wa tarda bi qada’ika wa takhshaka haqqa khashyatika
(O Allah, grant me a soul that firmly believes in meeting You, and is content with the provision You have apportioned me, and is satisfied with Your decree, and fears You as You ought to be feared.)