Letters I never knew disappear or get the L outa here

I am working my way through the psalms - and posting little as I study 'the vocabulary of recurrence', that is my 500 or so words that sound alike or have the same roots in the 19500 word forms in the psalter.

What do you make of psalm 49 - the verb acquire, לָקַח, get, actually drops the letter ל from the root like weak I-yod and I-nun verbs drop their yods and nuns!  I had not seen this before in studying letter behaviour among Hebrew word forms.

Only in psalm 49 - see text here - does this word recur as a potential frame in the psalter.

Here is the bit that is framed - selah - think about it.

you will not fear when someone becomes rich

for the increase of the glory of his house