suck out of one's thumb

Calque of Afrikaans uit sy duim suig, from Dutch uit zijn duim zuigen.

suck out of one's thumb (third-person singular simple present sucks out of one's thumb, present participle sucking out of one's thumb, simple past and past participle sucked out of one's thumb)

1. (South Africa, transitive, informal) To make up, to fabricate, to pull out of one's ass. [from mid 20th c.]
   • 1956, Debates of the House of Assembly (Hansard), Vol. 90/91/92, page 2185.

     One cannot lay a charge, a charge which has simply been sucked out of one's thumb, and then say that the onus rests on the person against whom the charge has been made, to prove that it is not so.

• pull out of one's ass
• talk through one's hat