LSt.29:6 :ܗ݀ܝ ܕܢܩܕܘܡ ܕܢܬܕܒܪ ܕܫܦܝܪ܂ ܡܓܗܝܐ ܠܐܢܫ ܡܢ ܡܬܬܘܝܢܘܬܐ‏ : that which one does well first saves one from regret
See the entire entry for mettawyānū, mettawyānūṯā n.f. regret