This is the 20th most frequent Malay word.
oleh
"By" or "through."
Here, 'oleh' is used to indicate the doer of the action in a passive voice sentence, attributing the action of reading to Ali.
Buku ini dibaca oleh Ali.
This book is read by Ali.
In this sentence, 'oleh' specifies the person who performed the action of making the cake in a passive construction.
Kek ini dibuat oleh ibu.
This cake is made by mother.
Here, 'oleh' identifies the entities supporting the research in a passive verb construction.