Following are a number of back-translations as well as a sample translation for translators of Leviticus 23:38:

• Kupsabiny: “Celebrate/Eat those festivals in addition to the days of Sabbath. Those offerings are an addition to the things that you (plur.) have promised to give to him or when a person gives out of love only.” (Source: Kupsabiny Back Translation)
• Newari: “These festivals are in addition to the Rest Days that you celebrate regularly, and the sacrifices that you offer are also in addition to the sacrifices that you regularly come to offer. And they are also in addition to the sacrifices that you offer to fulfil a promise that you made to the LORD.” (Source: Newari Back Translation)
• Hiligaynon: “You (plur.) are-to-celebrate these special times in- addition-to the Day For-Resting which you (plur.) observe/[lit. do] every week. And you (plur.) are-to-offer these offerings in-addition-to your (plur.) gifts, to your (plur.) offerings for fulfilling vows, and to your (plur.) freewill offerings that you (plur.) offer to the LORD.” (Source: Hiligaynon Back Translation)
• English: “Those festivals must be celebrated/You must celebrate those festivals in addition to worshiping on the Sabbath days/days of rest. And all those offerings must be given in addition to the offerings that people personally decide to give, and in addition to the offerings that people make to accompany the solemn promises that they have made, or offerings that people make voluntarily/because they themselves want to.” (Source: Translation for Translators)