((Remember) when the angels said: "O Maryam! Verily, Allah gives you the glad tidings of a Word from Him,) a son who will come into existence with a word from Allah, `Be', and he was. This is the meaning of Allah's statement (about Yahya)
مُصَدِّقاً بِكَلِمَةٍ مِّنَ اللَّهِ
(Believing in the Word from Allah.) 3:39, according to the majority of the scholars.
The previous verse (44) appeared parenthetically between the present verses 45 - 46 and verses 42 - 43 and the purpose was to affirm the prophethood of Sayyidna Muhammad ﷺ . The present verse resumes with the story of Sayyidah Maryam which actually pre-pares the ground for a fuller account of the birth, mission and miracles of Sayyidna 'Isa (علیہ السلام) .
Commentary
One of the qualities of Sayyidna 'Isa (علیہ السلام) mentioned in this verse is that 'he shall speak in the cradle' which means that he will speak while still a child, although no child has the ability to do so. When soon after the birth of infant Jesus (علیہ السلام) ، as mentioned in another verse, people chided Sayyidah Maryam on the basis of a false accusation, this new-born infant, Sayyidna ` Isa (علیہ السلام) spoke up, saying: اِنِّی عبداللہ (I am a servant of Allah). Then following immediately, it was said that he will also talk to people when he will be in the later middle of his age (kahl). It is worth noting here that the incidence of speaking in infancy was certainly a sign and a miracle and it is quite appropriate to mention it at this point. But, speaking to people during one's middle age is very normal, something everyone does no matter whether he is a Muslim, or a non-Muslim, learned or illiterate. Why has this been mentioned here as something special? what could it mean?
God blessed Zachariah (Zakariyya) with an offspring in his old age; provided sustenance to Mary in her shrine; created Jesus without a father, and brought into being chaste and upright people who were descendants of Abraham, so that they could be chosen to communicate the message of God to human beings. God did not grant these blessings to His people for no good reason: He found them so deserving that he showered them with His blessings. These were the people who had no material expectations from their children; their happiness rested upon their children’s dedication and devotion to the cause of God. These were the people who wanted their children to be safe from Satan and join the band of believers. They were not given to jealousy and ill-will on seeing goodness in others. It was through their good influence that their children too were in control of their selves and became one with those who truly remembered God: who chose the right way, abandoning the path that leads one astray. Such are the people whom God provides for out of His special mercy, and who have His special blessings showered upon them.
Uthmani text of the Madinah mushaf (King Fahd Complex). Translation: Saheeh International. Tafsir via Quran.com.
