John Gill Commentary Mark 1:35

"And in the morning, a great while before day, he rose up and went out, and departed into a desert place, and there prayed." — Mark 1:35 (ASV)

And in the morning, rising up a great while before day ,
&c.] On the morrow after the sabbath, on the first day in the morning, notwithstanding the fatigue of the former day, through preaching and working miracles; yet he rose up very early while it was very much within the night, as the light and day were coming on, and before the day broke; though it might be broad day before he departed out of the house, as Luke suggests, (Luke 4:42) ,

he went out ;
out of the house of Simon and Andrew, and out of the city of Capernaum, leaving his disciples and friends behind him:

and departed into a solitary place, and there he prayed ;
as man, to his God and Father; it may be for his disciples he had lately chosen; for himself, as man, that he might be strengthened as such for service; and for success in his ministry, and that his Gospel might run and be glorified; he chose a desert, and solitary place, for the sake of retirement, from the crowd of people that attended at Peter's door; where he could not be alone, and in private, and as most suitable for the exercise of prayer. His early and private devotion may be an example to us.