Tajrīd is not restricted to one particle. The key is the imagined counterpart, not a mandatory letter.
«لَئِنْ سَأَلْتَ فُلَانًا لَتَسْأَلَنَّ بِهِ الْبَحْرَ»
“If you ask that man, it is as though you ask the sea through him.”
The “sea” evokes overwhelming generosity as though another immense source of bounty could be drawn from the person. Constructions may use min, bi-, or no distinctive particle at all.
A simile merely notes likeness between sides; tajrīd specifically evokes an additional possessor of the quality extracted from the first.