The pronoun "he" refers to Jesus. Here "a third time" means "time number 3." AT: "Jesus said to him a third time" (See: [[rc://en/ta/man/translate/translate-ordinal]])
This time when Jesus asks this question he uses the word for "love" that refers to brotherly love or love for a friend or family member.
# Feed my sheep
Here "sheep" is a metaphor that represents those who belong to Jesus and follow him. AT: "Care for the people I care for" (See: [[rc://en/ta/man/translate/figs-metaphor]])