Xiānxiàshǒu wéi qiáng, wǒmen mǎshàng qiān hétong ba.
Strike while the iron is hot — let's sign the contract right now.
Tips
usage
先下手为强 is paired with the phrase 后下手遭殃 (hòu xià shǒu zāo yāng, 'those who act second suffer disaster') for emphasis. Together they form a proverbial couplet urging swift, preemptive action.