What is the meaning of "Tikon Tefilasi Ketores"?
Radak: My Tefilah should be like Ketores.
Malbim: Also my preparation for Tefilah should be considered like Ketores in front of You.
What is "Mas'as Kapai"?
Rashi: It is what I carry in my hands to You.
Malbim: It is lifting my hands in Tefilah.
What is "Minchas Arev"?
Radak: The same applies to Minchas Boker. Perhaps he composed this at night.
Radak citing his father: If the morning Minchah is proper, it is accepted. If the Minchas Arev is Tahor 1 , it is the second [proper Korban that day]; it is more accepted.
Malbim: It is what comes at the end, after Tefilah and Avodah is finished.
I.e. even if it is not so proper, as long as it is Tahor, it is accepted. (PF)