What does 戯んでいた mean?


This is found in the novel 空の境界(上), from "奈須 きのこ", the whole sentence is:

> 拵えが立派な細い刃物を手にして戯んでいたわたしは、いつのまにか指のあいだを深く切り裂いていました。

What does 戯んでいた mean? At first I thought it would be a verb ending in ぶ or む,
but it turns out it's not really a verb, I guess it's a noun. I found out that
for it to be a verb it should be "戯れる", so it's clearly not a "ている" form in
the past.




> 拵えが立派な細い刃物を手にして戯んでいたわたしは、 いつのまにか指のあいだを深く切り裂いていました。

Probably I would have guesstimated the word 戯{あそ}んでいた is the past progressive
form of 戯{たわむ}れる at first for reading the full sentence.

Usually 戯{たわむ}れる is more of "frolic"(ex. puppies chasing/tickling around) than
"play" : 遊{あそ}ぶ (I mean playing baseball could be very serious as a
profession, right?)

So, the author chose 戯{あそ}んでいる is appropriate to draw the agent seeing the
beautiful knife and making sure its performance and they happened to cut their
interdigital space deeply.

