The printer’s manuscript here reads claped. The single p is typical of Oliver Cowdery’s spelling practice; that is, he frequently neglected to double consonants after short vowels when adding an inflectional ending such as -ed (see the list of examples under Alma 11:2). Here in Alma 19:30, the 1830 typesetter accidentally misread claped as clasped, which ended up removing the more emotional, even pentecostal, clap of the original event in favor of the rather anemic clasp. Elsewhere in the text, the 1830 typesetter correctly interpreted Oliver Cowdery’s claped as clapped:
The example from Mosiah 18:11 is particularly relevant here since it represents the same situation as in Alma 19:30—namely, the spiritual joy of the moment leads participants to clap their hands, not clasp them. In fact, the word clasp is used only once in the actual Book of Mormon text, and the context there is completely different: “that they might have been clasped in the arms of Jesus” (Mormon 5:11). The 1908 RLDS edition restored the original clapped in Alma 19:30, as will the critical text.
Summary: Replace in Alma 19:30 the 1830 typesetter’s error clasped with the original reading, clapped (spelled by Oliver Cowdery in 𝓟 as claped ); the use of the verb clap is consistent with a similar event in Mosiah 18:11.