Mary never claimed so, but the Roman Catholic Church teaches such:
Mary, “the All-Holy,” lived a perfectly sinless life. (Catechism 411, 493)
Familiar? The doctrine of the Assumption is based on a sacred tradition that reflects an understanding of Mary's nature that dates back through the centuries.
Seems to me that Jesus took issue when man gave preference to TRADITION vice the Word of God:
Mat 15:1-8 Then some Pharisees and teachers of the law came to Jesus from Jerusalem and asked,
"Why do your disciples break the tradition of the elders? They don't wash their hands before they eat!"
Jesus replied, "And why do you break the command of God for the sake of your tradition?
For God said, 'Honor your father and mother' and 'Anyone who curses his father or mother must be put to death.'
But you say that if a man says to his father or mother, 'Whatever help you might otherwise have received from me is a gift devoted to God,' he is not to 'honor his father' with it. Thus you nullify the word of God for the sake of your tradition.
You hypocrites! Isaiah was right when he prophesied about you: " 'These people honor me with their lips, but their hearts are far from me.
No Sacred Tradition of the Catholic Church violates a command of God.
It is His Church, founded by Him and protected from error by the Holy Spirit to this day and for all time. Why would Christ violate His own command?
>>You hypocrites! Isaiah was right when he prophesied about you: “ ‘These people honor me with their lips, but their hearts are far from me. <<
Who are you talking about?