When the child begins to talk

Recite the following Ayah of the Qur'an first:

وَقُلِ الْحَمْدُ لِلَّهِ الَّذِي لَمْ يَتَّخِذْ وَلَدَاً وَلَمْ يَكُنْ لَهُ شَرِيكٌ فِي الْمُلْكِ وَلَمْ يَكُنْ لَهُ وَلِيٌّ مِنَ الذُّلِّ وَكَبِّرْهُ تَكْبِيرَاً

"Praise to Allah , who has not taken a son and has had no partner in [His] dominion and has no [need of a] protector out of weakness; and glorify Him with [great] glorification.". (QS 17:111)

and then:

لَا إِلَهَ إِلَّا اللَّهُ

"There is no god, except Allah"