I was eaten the day the white bull was eaten.- إنما أكلت يوم أكل الثور الأبيض

It is narrated that the Commander of the Faithful, Ali, may God be pleased with him, said: “My situation and that of Uthman is like that of three bulls in a thicket: one white, one black, and one red. A lion was with them, and he could not overcome them because they were all ganging up on him. He said to the black and red bulls: ‘Only the white bull can betray us in our thicket, for his color is well-known, and my color is the same as yours. If you would let me eat him, the thicket would be clear for us.’ They replied: ‘Go ahead and eat him.’ So he ate him. After some days, he said to the red bull: ‘My color is the same as yours, so let me eat the black one so that the thicket will be clear for us.’ He replied: ‘Go ahead and eat him.’ So he ate him. Then he said to the red bull: ‘I will inevitably eat you.’ The red bull replied: ‘Let me call out three times.’ He said: ‘Do so.’ So he called out: ‘I was eaten the day the white bull was eaten.’ Then Ali, may God be pleased with him, said: ‘I was humiliated.’ It is also narrated: ‘I was humiliated the day Uthman was killed.’ He raised his voice, saying, ‘I was humiliated the day Uthman was killed.’ He then struck the man, mourning the loss of his brother. 

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 The closest English equivalents are:

United we stand, divided we fall

“United we stand, divided we fall.”

This is the closest direct English proverb to the general meaning.

An injury to one is an injury to all

“An attack on one is an attack on all.”

If you don’t stand for others, no one will stand for you

“If you don’t stand with others, no one will stand with you.”

This is very close to the spirit of the story.

One by one

This is sometimes used to indicate that a group is defeated by gradual division.

The most famous English expression that corresponds to the proverb in wisdom and meaning is:

United we stand, divided we fall.

A literary translation of the same proverb is:

“I was eaten the day the white bull was eaten.”

This is sometimes known in literary and political translations because it carries a powerful symbol of disintegration and abandonment of others.

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يروى، أن أمير المؤمنين علياً، رضي الله تعالى عنه، قال: إنما مثلي ومثل عثمان كمثل أثوار ثلاثة كن في أجمة، أبيض وأسود وأحمر، ومعهن فيها أسد، فكان لا يقدر منهن على شيء لاجتماعهن عليه. فقال للثور الأسود والثور الأحمر: لا يدل علينا في أجمتنا إلا الثور الأبيض، فإن لونه مشهور ولوني على لونكما، فلو تركتماني آكله، صفت لنا الأجمة. فقالا: دونك فكله. فأكله. فلما مضت أيام قال للأحمر: لوني على لونك فدعني آكل الأسود لتصفو لنا الأجمة. فقال: دونك فكله. فأكله. ثم قال للأحمر: إني أكلك لا محالة. فقال: دعني أنادي ثلاثاً. فقال: افعل. فنادى، ألا إني أكلت يوم أكل أثور الأبيض. ثم قال علي رضي الله تعالى عنه: إلا إني هنت، ويروى: وهنت يومك قتل عثمان يرفع بها صوته يضربه الرجل، يرزأ بأخيه.