«يَجْعَلُونَ أَصَابِعَهُمْ فِي آذَانِهِمْ»
They put their fingers into their ears.
The word «أَصَابِع» normally denotes whole fingers, whereas in the described action the fingertips are inserted. The relation is wholeness (kulliyya): naming the whole while intending its part.
This is a helpful example of majaz in general, but it is not isti'ara. Its relation is whole-to-part rather than similarity, so it falls under majaz mursal, which is studied next.