The word(s) "voluntarily" appears 2 time(s) in 2 verse(s) in Quran in Mohsin Khan translation.

(1) Verily! As-Safa and Al-Marwah (two mountains in Makkah) are of the Symbols of Allah. So it is not a sin on him who performs Hajj or 'Umrah (pilgrimage) of the House (the Ka'bah at Makkah) to perform the going (Tawaf) between them (As-Safa and Al-Marwah). And whoever does good voluntarily, then verily, Allah is All-Recogniser, All-Knower.

(2) Those who defame such of the believers who give charity (in Allah's Cause) voluntarily, and such who could not find to give charity (in Allah's Cause) except what is available to them - so they mock at them (believers); Allah will throw back their mockery on them, and they shall have a painful torment.