The Messenger of Allah ﷺ would invoke blessings upon the first row three times and upon the second row once.
أخبرني يحيى بن عثمان الحمصي قال حدثنا بقية عن بحير بن سعد عن خالد بن معدان عن جبير بن نفير
عن رسول الله ﷺ كان يصلي على الصف الأول ثلاثا وعلى الثاني واحدة
[Sahih] Ahmad narrated it, 4/128, from the hadith of Baqiyyah with this chain, and he explicitly stated hearing it there. It is also in al-Kubra, hadith 891. Hakim graded it sahih, 1/214, and Dhahabi agreed with him. Ibn Majah also narrated it, hadith 996, from the hadith of Khalid bin Madan from Irbad with this chain.