Here the 1953 RLDS edition made this whole passage into a direct quote. In the original text (which is wholly extant in the original manuscript), the first part of the passage is a direct quote (thus “my commandments”), but the second part is an indirect quote (“his commandments … his presence”). A similar example of this kind of mixture (a direct quote for the positive form of the promise, immediately followed by an indirect quote for the negative form of the promise) is found in 2 Nephi 1:20. In that instance, Oliver Cowdery made the correction of his to my in 𝓞 itself, but only later. Thus the original readings in 2 Nephi 1:20 and in Alma 37:13 support each other. The original use of his here in Alma 37:13 will be maintained in the critical text. For an extensive discussion of how this promise is quoted throughout the text, in both its positive and negative forms, see under 2 Nephi 1:20.
Summary: Accept in Alma 37:13 the switch from a direct quote (in positive form) to an indirect quote (in negative form) of the Lord’s promise that he originally gave to Nephi and Lehi; the same switch in usage can be found originally in 2 Nephi 1:20.