An iʿtibar is an aspect taken into account. The appropriate consideration is the aspect that the rhetorical occasion makes relevant.
If the audience already accepts a report, adding solemn oaths may burden the sentence. If the audience strongly denies it, reinforcement may be fitting.
Likewise, an appeal to someone who needs reassurance differs in tone from a grave warning directed at someone persisting in harm.
There is no one fixed wording that counts as the suitable consideration in every case; the purpose and the audience's condition determine it.