LSt.29:7 :ܡܚܡܣܢܢܘܬܐ ܢܟܘܝܬܐ ܗܝ ܕܛܠܝܘܬܐ܂ ܘܐܦܢ ܠܡܝܬܪܘܬܐ ܢܓܕܐ ܠܗ‏ : perseverance is that which is harmful to youth, even if it leads to excellence
See the entire entry for mḥamsnānū, mḥamsnānūṯā n.f. constancy