गुरूनहत्वा हि महानुभावान् श्रेयो भोक्तुं भैक्ष्यमपीह लोके।हत्वार्थकामांस्तु गुरूनिहैव भुञ्जीय भोगान् रुधिरप्रदिग्धान्॥
gurūnahatvā hi mahānubhāvānśreyo bhoktuṃ bhaikṣyamapīha lokehatvārtha-kāmāṃstu gurūnihaivabhuñjīya bhogān rudhira-pradigdhān
Word by word
The verse says
Better to live on begged food in this world than to kill these great-souled teachers. If I killed them, even for gain, everything I ate afterwards would be smeared with their blood.
In plain words
He would rather beg. He says it plainly.
For a prince this is not a figure of speech. Begging is the bottom of the social order, the opposite of everything he was raised to be. He is saying he would take that over the throne.
Then the image at the end, which is the part that sticks: food covered in blood. He is not talking about guilt in the abstract. He is talking about eating.
Where you've felt this · with money
Money arrives from a source you are not easy about, and it spends exactly like any other money. That is the problem. Every ordinary thing you buy with it has the same faint taste.
Going deeper
Arjuna has found the strongest form of his own case, and the Gita lets him state it fully.
He is arguing about contamination. Not the act would be wrong, but the whole life after it would be spoiled. That is a serious moral intuition, and it is one most people share. You can win something and find the winning has ruined it.
Hold this against Krishna's answer in 2.47, and the shape of the disagreement becomes clear. Arjuna assumes the act and its fruit are one thing, so a poisoned outcome means a poisoned act. Krishna will separate them — and the separation is what makes an answer possible at all.
Notice too that Arjuna keeps reaching for enjoyment: bhoktum, bhogān, to eat, to enjoy. He is measuring the whole question by what it will be like to be him afterwards. That measure is exactly what Krishna takes away, not because pleasure is wicked, but because it cannot bear the weight of deciding what to do.