Proverbs 21:13 New English Translation

¹³The one who shuts his ears^[a] to the cry^[b] of the poor,
he too will cry out and will not be answered.^[c]

Proverbs 21:13 sn The imagery means “pay no attention to” the cry for help or “refuse to help,” so it is a metonymy of cause for the effect.
Proverbs 21:13 sn “Cry” here would be a metonymy of effect for the cause, the cause being the great needs of the poor.
Proverbs 21:13 sn The proverb is teaching that those who show mercy will receive mercy. It involves the principle of talionic justice—those who refuse the needs of others will themselves be refused when they need help (so Luke 16:19-31).

New English Translation (NET)