约言

lǚ xíng yuē yán

履行约言

redeem one's pledge

wéi fǎn yuē yán

违反约言

go back on one's word

yǒu yì de yuē yán

友谊的约言

pledge of friendship

wǒ men dōu děi zhào yuē yán xíng shì

我们都得照约言行事。

We should abide by the agreement.