Here Oliver Cowdery started to write “for behold he saith that … ” , but he aborted writing the that (he did not cross the final t ) and overwrote the at with ou, thus immediately replacing the subordinate conjunction that with the subject pronoun thou; then he wrote the rest of the clause inline, giving “for behold he saith : thou hast turned away thy judgments because of thy Son”. Oliver was expecting the verb say to introduce an indirect quote, thus his initial that. But the following quote is a direct quote. Undoubtedly the original text had the direct quote. For some discussion of the optionality of that after the verb say, see under 2 Nephi 30:2. Also see the general discussion under that in volume 3.
Summary: Accept in Alma 33:13 the corrected reading in 𝓞, namely, without that before the direct quote “thou hast turned away thy judgments because of thy Son”.