As discussed under Alma 12:8, scribe 2 of 𝓟 frequently omitted the conjunction and. In this instance, Oliver Cowdery provided the and when he proofed 𝓟 against 𝓞. Here the and is expected between the two participial clauses. The critical text will maintain Oliver’s corrected reading in 𝓟.
Summary: Accept the and that Oliver Cowdery inserted in Alma 13:3; the and was probably the reading of the original manuscript, no longer extant here.