Narrated Zaid bin Arqam: We used to speak while in prayer. One of us used to speak to his brother (while in prayer) about his need, till the Verse was revealed:-- "Guard strictly the (five obligatory) prayers, especially the middle (the Best) (`Asr) Prayer and stand before Allah with obedience (and not to speak to others during the prayers)." Then we were ordered not to speak in the prayers.

Narrated Zaid bin Arqam: In the lifetime of the Prophet we used to speak while praying, and one of us would tell his needs to his companions, till the verse, 'Guard strictly your prayers (2.238) was revealed. After that we were ordered to remain silent while praying.