«قُصْر دِيلْ يَا ازْعَرْ»

The saying punctures a pretense of restraint. Someone claims, or appears, to be choosing not to take part in something, but the speaker insists the true cause is simple incapacity: the person lacks the means, reach, or strength to do it at all, so their abstention earns no credit.

The imagery addresses a tailless creature whose 'short tail' is really no tail at all. The point is missing means rather than mere smallness: what it lacks entirely, it cannot be praised for holding still. The line thus exposes inability disguised as modesty, discipline, or principled refusal.

Said to someone who presents staying out of an undertaking as a deliberate choice, when the speaker believes the real reason is lack of ability or resources. Calling someone 'tailless' is a jibe, so it can insult; it suits only teasing among familiars.