en_tn/mrk/03/21.md

they went out to seize him

Members of his family went to the house so that they could take hold of him and force him to go home with them.

for they said

Possible meanings for the word "they" are 1) his relatives or 2) some people in the crowd.

out of his mind

Jesus' family uses this idiom to describe how they think he is acting. Alternate translation: "crazy" or "insane" (See: rc://en/ta/man/translate/figs-idiom)