to stretch one's arm no further than one's sleeve (will reach)
/stɹˈɛtʃ wˈʌnz ˈɑːɹm nˈoʊ ˌɛni fˈɜːðɚ ðɐn wˈʌnz slˈiːv wɪl ɹˈiːtʃ/
phraseThe origin of this idiom is not clear, but it likely developed from the idea of being cautious and not overreaching or attempting more than one can handle.
