Isaiah 28:10; Isaiah 28:13

10 so that [one has to use nursery rhymes]? Tzav la-tzav, tzav la-tzav, kav la-kav, kav la-kav z'eir sham, z'eir sham [Precept by precept, precept by precept, line by line, line by line, a little here, a little there].

13 So now the word of ADONAI for them comes "precept by precept, precept by precept, line by line, line by line, a little here, a little there," so that when they walk, they stumble backward, and are broken, trapped and captured!