Reference: Muwatta Maalik, no.301
‘Umar ibn al-Khattaab missed Sulaymaan ibn Abee Hathmah at the morning (Fajr) prayer. In the morning he went to the market, and [since] Sulaymaan’s house was between the market and the Prophet’s masjid – he [happened to] pass by ash-Shifaa – Sulaymaan’s mother – and said to her:
I did not see Sulaymaan in the morning [Fajr prayer].
He spent the night in prayer and [the sleep in] his eyes overcame him.
[In response to her] ‘Umar said:
That I were to attend the morning (Fajr) prayer in congregation is indeed more beloved to me than if I were to stand the [whole] night in prayer.