الهيئات تدل على الصفة لا لاختصاصها بمن هي له
Scenes or conditions signify a trait without being exclusive to any one bearer of it.
A welcoming face, warmth toward visitors and promptness in generosity can occur in different people. A poet's use of such signs therefore does not automatically show borrowing from another poet.
The case becomes stronger only if a distinctive literary invention, not merely a conventional sign, appears to have been carried over.