Following are a number of back-translations of Matthew 5:35:

• Uma: “But I say: don’t swear/make vows at all. If we (incl.) make a promise, don’t swear naming the sky or earth. Because the sky is the sitting-place of God and the earth is his stepping-place. Don’t swear naming the city of Yerusalem, because that is the city of God the big King.” (Source: Uma Back Translation)
• Yakan: “But I, I say: if you promise anything do not swear calling on (lit. uttering) heaven, because there is the sitting place of God. Do not swear calling on the earth because this is the resting place of God’s feet. Do not swear calling on the city of Awrusalam because this is the city ruled/held by the Most Powerful King.” (Source: Yakan Back Translation)
• Western Bukidnon Manobo: “And I say to you, if there is that which you promise to anyone, don’t you swear saying that may heaven and earth where you stand collapse if what you say isn’t true, because heaven is where God sits and the earth is where his feet rest. And don’t you also say that may the town of Jerusalem be destroyed if what you say isn’t true, because that’s where the great king will live.” (Source: Western Bukidnon Manobo Back Translation)
• Kankanaey: “Don’t moreover say, ‘Look you (sing.) earth,’ because that is where he stretches-out his legs, or ‘Look you (sing.) Jerusalem,’ because that’s the town of the high King.” (Source: Kankanaey Back Translation)
• Tagbanwa: “Or say, ‘The world is my witness,’ because this is like the stool of his feet. Also don’t say, ‘Jerusalem is my witness,’ because this is the city of the praiseworthy King.” (Source: Tagbanwa Back Translation)
• Tenango Otomi: “Do not call upon earth as a witness because it is God who rules all the earth, it is as though you called upon him as a witness. Do not call upon the city of Jerusalem as a witness, because it is there God is the king, it is as though you called upon him as a witness.” (Source: Tenango Otomi Back Translation)

For the Old Testament quote, see Psalm 48:2.