Srimad-Bhagavatam: Canto 11 - Chapter 1 - Verse 49


शूद्रवृत्तिं भजेद् वैश्य: शूद्र: कारुकटक्रियाम् ।कृच्छ्रान्मुक्तो न गर्ह्येण वृत्तिं लिप्सेत कर्मणा ॥ ४९ ॥


śūdra-vṛttiṁ bhajed vaiśyaḥśūdraḥ kāru-kaṭa-kriyāmkṛcchrān mukto na garhyeṇavṛttiṁ lipseta karmaṇā


A vaiśya, or mercantile man, who cannot maintain himself may adopt the occupation of a śūdra, and a śūdra who cannot find a master can engage in simple activities like making baskets and mats of straw. However, all members of society who have adopted inferior occupations in emergency situations must give up those substitute occupations when the difficulties have passed.