Abdullah bin Abdullah bin Ubayy (r.a.)
Hz. Abdullah was from Madinah. He became a Muslim before the Migration. His real name was Hubab. The Prophet changed his name to "Abdullah" because he did not like his name. Abdullah was adherent to the Prophet with all his heart. There was no sacrifice that he could not make for him. He participated in all wars.
Ironically, his father, Abdullah bin Ubayy, was a famous hypocrite. The reason why he did not believe was his hatred against the Messenger of Allah. For, he was one of the notables of the Khazraj tribe. He was rich and he was liked by his tribe very much. He was a knowledgeable and shrewd man. He was about to become the ruler of Madinah when the Migration took place and the Islamic State was established. This disturbed him a lot. He became an enemy of the Prophet. He did a lot of bad things to the Messenger of Allah and Muslims with the people around him. However, when they saw that the Prophet became stronger day by day, they had to say that they became Muslims. Nevertheless, they did not cease betraying Muslims when they found opportunities and demoralizing the Muslims.
For example, before the Battle of Uhud began, he returned to Madinah with his men, who constituted a third of the Islamic army. Eventually, the Islamic army was defeated.
Abdullah bin Ubayy's son, Hz. Abdullah, fought heroically in this battle and was wounded in a few places. Two of his teeth were broken. His father was very happy about it. He said,
"If you had obeyed me instead of obeying Muhammad, who acted in accordance with the views of young people, you would not have been wounded."
Hz. Abdullah was very sorry that his father was pleased with what had happened to him. He believed that there was something good in this outcome. He said to his father,
"There is certainly something good and wisdom in what Allah predestinated."
Abdullah bin Ubayy took part in Sons of Mustaliq Expedition too. His purpose was to cause mischief and disorder. He addressed the hypocrites (munafiqs) around him as follows:
“When we return to Madinah, the honored and strong ones will expel the mean and weak ones from the city. You brought them to your city; you shared your goods with them. If you had not done so and if you had treated them harshly, they would have gone somewhere else. You died for the Prophet and your children became orphans; your number decreased. Do not give zakah and sadaqah to the people around him so that they will go away.”
When Hz. Abdullah heard the statement of his father, he became very sorry. He went into the presence of the Prophet at once and said to him,
“O Messenger of Allah! If you want to kill my father for his words that I heard, order me to do it and I will bring his head to you. All of the people of Khazraj know that there is nobody among them who loves and respects their father more than I do. If you let somebody else kill him, I will not put up with it when I see the killer of my father around. I might kill a believer in return for an unbeliever and go to Hell.”
The Prophet did not allow him to do it lest it should cause some rumors. He said,
“No. We will treat your father leniently and act as friends as long as he is among us.”
Hz. Abdullah could not possibly forget the words of his father about the Messenger of Allah. He wanted to punish his father. He could not put up with it any more. He proceeded and stopped in the way of his father. He said,
“I will not let you go unless you say majesty and power belong to Allah and His Messenger!” His father was astonished. He said,
“You say you will not let me go to Madinah Is that right?” Hz. Abdullah said,
“I will kill you unless you say majesty and power belong to Allah and His Messenger.”
When the Abdullah bin Ubayy realized that his son was determined, he had to say,
“I witness that majesty and power belong to Allah, His messenger and believers.”
The Prophet became very pleased due to this attitude of Abdullah and prayed for him by saying,
“May Allah reward you with goodness!” Then, he ordered Abdullah to release his father.
Hz. Abdullah, who was a hero of belief, served Islam until he died. He took part in the Battle of Yamama in 12 H. He fought heroically there. He was wounded in a few places. Then, he became a martyr. May Allah be pleased with him! 
Tabaqat, 2: 65; 3: 540-541; Mustadrak, 3: 488. Usdul-Ghaba, 3: 197.