In this passage Oliver Cowdery twice wrote speak rather than the expected spake in the printer’s manuscript (numbered above as 1 and 2). Only in the third case did he get the correct spake. In the original manuscript, the first two instances of spake are partially extant. In the first case, only the final e of spake is extant in 𝓞, but we can tell that it is the final e (there is no following ak ). In the second case, only the ascender of the k is extant; the ascender for the first l in the following word plainly is also extant, but it is difficult to determine from the spacing whether the original read spake or speak, although I presume that it did read spake. The third case is not at all extant in 𝓞. The 1830 compositor set all three instances as spake.
There is the theoretical possibility that these instances of spake read as spoke in the original manuscript. Yet usage elsewhere in the text argues that in the original text the simple past-tense form for the verb speak was consistently spake, not the modern spoke. For a complete discussion, see under 1 Nephi 12:19; also see under past tense in volume 3.
Summary: Accept in Jacob 7:17–18 the 1830 compositor’s decision to emend two instances of speak to spake; the context requires the past tense, and spake (not spoke) is the consistent past-tense form for the verb speak.