Here are some lyrics from Hush, Little Baby. Verses 4 and 5 have the "hook and line" lyric:

Hush, Little Baby
                                 
1.Hush, little baby, don't say a word, Papa's goin' to buy you a talkin' bird;
2.If that talking' bird don't sing, Papa's goin' to buy you a diamond ring;
3.If that diamond ring don't shine Papa's goin' to get you a hook and a line;
4.Hook and line don't catch you a fish, Papa's goin' to get you a silver dish;
5.If that silver dish gets broke, Papa's goin' to get you a nanny-goat;
6.If that nanny-goat should go dry, Papa's goin' to get you a butterfly;
7.If that butterfly fly away, Papa's goin' to rock his baby all day.

How does this relate to our 'Hook and Line' thread?

Richie