無根無據 [无－无据]

Jyutping mou4 gan1 mou4 geoi3
Pinyin wú gēn wú jù

Definitions (Wiktionary)
  1. phrase, Hakka, idiomatic
    mere verbal statement is no guarantee
    (syn.) 空喙哺舌, 空口无凭, 空口無憑, 口说无凭, 口說無憑