ἀλλὰ διὰ τῆς ἀγάπης δουλεύετε ἀλλήλοις. ὁ γὰρ πᾶς νόμος ἐν ἑνὶ λόγῳ πεπλήρωται, ἐν τῷ Ἀγαπήσεις τὸν πλησίον σου ὡς σεαυτόν → but be enslaved to each other through love; for the whole Torah is fulfilled in one statement: You will love your neighbor as yourself (Galatians 5:13f.)
from ἐν and the base of τέλος; to enjoin: (give) charge, (give) command(-ments), injoin.