Abu Dhubyan (may Allah have mercy on him) says that once we asked Sayyiduna Ibn Abbas (may Allah be pleased with them both) about «﴿مَا جَعَلَ اللّٰهُ لِرَجُلٍ مِنْ قَلْبَيْنِ فِي جَوْفِهِ﴾ [الأحزاب: 4] » "Allah has not made for any man two hearts in his chest," what does this command of Allah Almighty mean? He replied that once the Prophet (peace and blessings be upon him) stood to lead the prayer, and during the prayer a thought came to him, so the hypocrites who used to pray with the Prophet (peace and blessings be upon him) said: Do you not see that he has two hearts, one heart with you and one heart with them? Upon this, Allah Almighty revealed this verse.